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Thread ID: 67759	2006-04-05 04:12:00	Power Supply went boom! Mobo dead?	bob_doe_nz (92)	Press F1

Post ID	Timestamp	Content	User
443979	2006-04-05 04:12:00	My cousin has asked me to fix his computer which has apparently had a Power Supply go POP on him. Taking a deep sniff of the PS you can smell something burnt to a crisp. From what I can tell everything but the motherboard survived the incident. I have temporarily replaced the power supply with mine and tried to get the computer to boot to see if there is any damage, but for some reason the mobo will not confirm a POST with a beep. This is when all thats connected to the motherboard is the Graphics Card, 56k Modem, and RAM and CPU. I can press the power button and the computer will turn on, and I have noticed that the HDD LED is constantly on and never turning off. The Floppy disk drive if plugged in will not boot. AND I have tried removing the battery and replacing after 5 mins. Case of fried motherboard??? Comp specs if you need it... Asus P4P800 MOBO. Pentium 4 2.8 GHz I think Hyena 300W Power Supply. (Yes I know! That was what was in there for 2 years) DDR SDRAM, single stick (unknown size) Seagate HDD Geforce FX graphics	bob_doe_nz (92)
443980	2006-04-05 04:18:00	I would check and see if you notice any blown capacitors. I'm using the same mobo here. Did you connect the 4 pin ATX connection from the PSU to the mobo as well? Does the green LED on the mobo light up, when you turn the power on??	Speedy Gonzales (78)
443981	2006-04-05 04:27:00	No, Yes, Yes. Erm, how does blown capacitors on a motherboard come from a power supply that went pop?	bob_doe_nz (92)
443982	2006-04-05 04:34:00	Ok . If the LED is ON, thats a good sign . At least power is getting to it . If the screen comes on, I would go into the BIOS and set the default settings, and reconfigure the BIOS . See what happens then . Pass, the capacitors were just a guess :D The P4P800 doesnt beep on POST btw . Depending on which BIOS update is on it . ASUS with the latest versions of the BIOS (I think from 1004 up), disabled the beeps . Because it caused confusion with USB devices that were plugged into the USB ports . And the beep for the post . People couldn't tell whether there was prob or not . It used to beep for every USB device that was plugged into the USB ports .	Speedy Gonzales (78)
443983	2006-04-05 06:09:00	You'll have to check everything. Take all the bits out and test them one by one on another working PC - ram, graphics, HDD, CD/DVD, etc etc	pctek (84)
443984	2006-04-05 10:27:00	OK I've narrowed it down to the Mobo or CPU or both . Anyone have a spare Socket 478 CPU I can borrow? :blush: Oh Speedy one quick question . . . When you turn on the power at the wall, do the three lights (Num lock, Caps lock, Scroll Lock) on your keyboard blink once? (Assuming your using a PS2 keyboard . )	bob_doe_nz (92)
443985	2006-04-05 10:39:00	OK I've narrowed it down to the Mobo or CPU or both . Anyone have a spare Socket 478 CPU I can borrow? :blush: Yup, I have one here . Its a 1 . 5 400mhz, but will work in a P4P800 . I used it when the CPU died in this, a while back . When it went back to Malaysia to get replaced . When the power 1/2 killed it . Oh Speedy one quick question . . . When you turn on the power at the wall, do the three lights (Num lock, Caps lock, Scroll Lock) on your keyboard blink once? (Assuming your using a PS2 keyboard . ) It does indeed . Just tried it, with the power switch on the case turned on that is . The LED's on the keyboard (which is PS/2 - 4 LED's, caps, num lock, scroll and a special key) flashed once, and went off . If the CPU was dead, I doubt the system would boot up, or anything would appear on the screen . If it shows the CPU speed on the post screen, I doubt very much that the CPU is stuffed . Altho when 1/2 of this CPU died, it would still boot into XP, BUT it would crash often, like every 20-30 mins .	Speedy Gonzales (78)
443986	2006-04-05 12:01:00	Is the IDE cable to the Hard Drive in the wrong way? That's the only reason I can think it'd stay continously on, that or the reset switch is hardwired on. If its not connected, I don't think it should be on at all (though can't remember if that's true). Also, the most minimalistic things you require is PSU/CPU/Motherboard/RAM/Video/Keyboard and in some cases FDD but everything else, including the Hard Drive can be disconnected. Actually you can try with even less, PSU/CPU/Motherboard but the other things should at least force an error of the BIOS in some ways, hopefully beep codes. If power gets to the motherboard then to the hard drive activity LED then power should be good, do the system fans come on? Although system fans doesn't mean the CPU is fully functional, this is the red LED light right? You're not saying the hard drive is the green case lights to say it's powered on (though this still says power is going through the motherboard). What sort of power supply was the old one, what was it's watt rating, what is your power supply and it's rating? When power supplies go pop, sometimes it's due to surges or incorrect voltage setting. Could open it up and see if the fuse has gone, most likely not as I find other things blow before the fuse (silly I think), because it's hard to tell the smell of something burnt and the build up of years of dust. Just don't go poking around with your screwdriver in it, as the capicitors might still hold large charges. Also when testing the power supply, make sure it's grounded to the case that you're testing. Cheers, KK	Kame (312)
443987	2006-04-05 12:08:00	If power gets to the motherboard then to the hard drive activity LED then power should be good, do the system fans come on?Fan goes on. Also I left the HDD unplugged but the HDD light remained on. What sort of power supply was the old one, what was it's watt rating, what is your power supply and it's rating?Hyena 300Watt (aka el cheapo) Also when testing the power supply, make sure it's grounded to the case that you're testing. Don't need to worry about that any more, its in the trash minus the actually good ball bearing fan	bob_doe_nz (92)
443988	2006-04-05 12:17:00	I'm saying motherboard is fried, did you actually test his power supply in your own computer? I guess because he said it went pop, that may have been a reason why you never tried it, but the pop could have been on the board, unless he saw the sparks fly from it. Cheers, KK	Kame (312)
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